Gold alloy



Patented Oct. 8, 1929 UNITED STATES,

PATENT OFFICE VICTOR D. DAVIGNON, OF A TTLEBOR O, MASSACHUSETTS, ASSIGNOR TO GENERAL PLATE COMPANY, OF ATTLEBORO, MASSACHUSETTS, A CORPQRATION OF RHODE ISLAND GOLD ALLoY No Drawing.

probably on account of their strong atlinity for oxygen, cannot be alloyed with gold by usual processes to produce homogeneous, m alleable and ductile alloys. Althoughthe metals mentioned belong to the group of metals which have as a distinguishing characteristic the ready alloying with iron it is to be understood that the invention is not limited to use of metals of this group, as other low specific gravity metals, for example aluminum, which does not readily alloy with iron but which has a strong aflinity for oxygen, can be al.- loyed with gold by use of the process.

According to the practice of the inventlon the constituents of the alloy are melted in the presence of suitable fluxes to eliminate the oxides of the low specific gravity metals, with the result that a homogeneous alloy suitable for use in usual'mill processes is produced. Preferably but .not. necessarily thev constituents are melted with a metal which will facilitate the combining of the low specific gravity metal with the gold. I In producing goldcopper alloys I have found small amounts of manganese, say in amounts equal 0 1% of the weight of the alloy, will give sa isfactory results, which I explain is due tothe manganese causing the low specific gravity metal to combine with the copper, the latter readily combining with the gold.

As suitable for flux I may use potassium bifiuoride, calcium chloride, cryolite, potassium I chloride, sodium chloride, and sodium fiuof ride, a mixture consisting of 1 part calcium chloride and 2 parts potassium bifluoride being very satisfactory.

Application as June 10,

1926. Serial No. 115,115.

By practice of the improved method commercial gold alloys containing from 25 to 85% by weight of gold and silicon in amounts up to 1 or titanium in amounts up to 1% may be readily produced, and with care the amounts of silicon and titanium may be raised to-about'3% of the alloy. Smallamounts of these low specific gravity metals, as for example 1% of silicon or even less, will have a marked effect upon the specific gravity of the resulting allow.

As a desirable commercial 12 carat" green gold alloy the same may contain by weight about 50% gold, 12% copper, 1%72; silicon,

1% manganese, and the remainder silver, while as'a desirable commercial 12 carat yellow gold alloy the same may contain by weight about 50% gold, 1 silicon, 1% manganese, and theremainder copper. In the green gold alloy part of the silver may be replaced by aluminum, and in the yellow gold alloy part of the copper may be replacedby aluminum, pay in amounts equal to about 3% of the al- As an example of the practice of the method, but without limitation thereto, 1.5 troy ounces of silicon, 1 troy ounce of manganese, 47 .5 troy ounces of copper and 50 troy ounces of gold, all in small pieces, may be placed in a graphite crucible, say one about 4 inches in diameter at the top and about 8 inches high, the metals being arranged on top of each other in'the order of their specific gravities, the silicon on the bottom and the goldon} the top, while over the metals is placed about l ounce of a flux consisting of the mixture of calcium chloride and potassium bitluoride hereinbefore referred to. The crucible is now placed in a furnace and with a' carbon rod thoroughly to mix them, and if necessary additional flux being added to maintain on the molten metals a layer of flux about 4 inch thick. After melting, the

contents of'the crucible, that is the molten metals together with theslag and flux, are poured into a mold and allowed to cool, the

mold conveniently being of iron and havinga mold chamber about 10 inches long, which chamber in cross-section is a rectangle about x2 inches, the long axis of the chamber being at about 4.5 degrees to the horizontal, with the sides of greatest Width in vertical planes.

Although I have described several examples of alloys and metals for use therein, one example of the improved method and several examples of fluxes for use therewith, it is to be understood that Within the scope of my invention wide deviations may be made without departing from its spirit. v

Claims: I v

1. A gold alloy containing by Weight about 50% gold, from 1 to 3% silicon, 1% manganese, and the remainder copper.

2. ll gold alloy containing by Weight I about 50% gold, from 1 to 3% silicon, 3%

' 1y metal of the aluminum, 1% manganese, and the remainder copper.

3. A gold alloy containing by Weight about 50% gold, from 1 to 3% of metal of the group comprising silicon and titanium,

about 1% manganese, the remainder predominantly consisting of metal of the group comprising copper and silver.

4. Homogeneous malleable and ductile gold alloys containing by Weight from 25% i to 85% gold, metal of the group comprising silicon and titanium up to 3%, the remainder being predominately metal of the group comprising copper and silver.

5, Homogeneous malleable and ductile gold alloys containing by Weight from 25% to 85% gold, a substantial amount of silicon up to 3%, the remainder being predominategroup comprising copper and silver.

6. Homogeneous malleable and ductile gold alloys containing by weight from 25% to 85% gold, a material amount of silicon up to 3%, a small but substantial amount of predomimanganese, the remainder being nately copper.

Homogeneous malleable and ductile gold alloys containing by Weight from 25% to 85% gold, a material amount of metal of t e group comprlsing silicon and titanium up to 3%, a small but substantial amount 01 manganese, the remainder being predominately metal of the group comprising copper and silver.

,8. Homogeneous malleable and ductile I gold alloys containing by Weight from 25% to 85% gold, metal of the group comprising -silicon and titanium up to 3%, a substantial amount of aluminum up to 3%, a small but substantial amount of manganese, the remainder being predominately metalofthe 7 group comprising copperand silver.

In testlmony whereof, I have "signed my name to this specification.

VICTOR *1) DAVIGNQN: I 

